Standardized measurement of the future liver remnant prior to extended liver resection: methodology and clinical associations

Liver surgery in cirrhosis and portal hypertension

The prevalence of hepatic cirrhosis in Europe and the United States, currently 250 patients per 100000 inhabitants, is steadily increasing. Thus, we observe a significant increase in patients with cirrhosis and portal hypertension needing liver resections for primary or metastatic lesions. However, extended liver resections in patients with underlying hepatic cirrhosis and portal hypertension still represent a medical challenge in regard to perioperative morbidity, surgical management and postoperative outcome. The Barcelona Clinic Liver Cancer classification recommends to restrict curative liver resections for hepatocellular carcinoma in cirrhotic patients to early tumor stages in patients with Child A cirrhosis not showing portal hypertension. However, during the last two decades, relevant improvements in preoperative diagnostic, perioperative hepatologic and intensive care management as well as in surgical techniques during hepatic resections have rendered even extended liver resections in higher-degree cirrhotic patients with portal hypertension possible. However, there are few standard indications for hepatic resections in cirrhotic patients and risk stratifications have to be performed in an interdisciplinary setting for each individual patient. We here review the indications, the preoperative risk-stratifications, the morbidity and the mortality of extended resections for primary and metastatic lesions in cirrhotic livers. Furthermore, we provide a review of literature on perioperative management in cirrhotic patients needing extrahepatic abdominal surgery and an overview of surgical options in the treatment of hepatic cirrhosis.

Liver-fat and liver-function indices derived from Gd-EOB-DTPA-enhanced liver MRI for prediction of future liver remnant growth after portal vein occlusion

OBJECTIVES

To evaluate the use of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI)-derived fat- and liver function-measurements for prediction of future liver remnant (FLR) growth after portal vein occlusion (PVO) in patients scheduled for major liver resection.

METHODS

Forty-five patients (age, 59 ± 13.9 y) who underwent Gd-EOB-DTPA-enhanced liver MRI within 24 ± 18 days prior to PVO were included in this study. Fat-Signal-Fraction (FSF), relative liver enhancement (RLE) and corrected liver-to-spleen ratio (corrLSR) of the FLR were calculated from in- and out-of-phase (n=42) as well as from unenhanced T1-weighted, and hepatocyte-phase images (n=35), respectively. Kinetic growth rate (KGR, volume increase/week) of the FLR after PVO was the primary endpoint. Receiver operating characteristics analysis was used to determine cutoff values for prediction of impaired FLR-growth.

RESULTS

FSF (%) showed significant inverse correlation with KGR (r=-0.41, p=0.008), whereas no significant correlation was found with RLE and corrLSR. FSF was significantly higher in patients with impaired FLR-growth than in those with normal growth (%FSF, 8.1 ± 9.3 vs. 3.0 ± 5.9, p=0.02). ROC-analysis revealed a cutoff-FSF of 4.9% for identification of patients with impaired FLR-growth with a specificity of 82% and sensitivity of 47% (AUC 0.71 [95%CI:0.54-0.87]). Patients with impaired FLR-growth according to the FSF-cutoff showed a tendency towards higher postoperative complication rates (posthepatectomy liver failure in 50% vs. 19%).

CONCLUSIONS

Liver fat-content, but not liver function derived from Gd-EOB-DTPA-enhanced MRI is a predictor of FLR-growth after PVO. Thus, liver MRI could help in identifying patients at risk for insufficient FLR-growth, who may need re-evaluation of the therapeutic strategy.

Portal vein embolization for induction of selective hepatic hypertrophy prior to major hepatectomy: rationale, techniques, outcomes and future directions

The ability to modulate the future liver remnant (FLR) is a key component of modern oncologic hepatobiliary surgery practice and has extended surgical candidacy for patients who may have been previously thought unable to survive liver resection. Multiple techniques have been developed to augment the FLR including portal vein embolization (PVE), associating liver partition and portal vein ligation (ALPPS), and the recently reported transhepatic liver venous deprivation (LVD). PVE is a well-established means to improve the safety of liver resection by redirecting blood flow to the FLR in an effort to selectively hypertrophy and ultimately improve functional reserve of the FLR. This article discusses the current practice of PVE with focus on summarizing the large number of published reports from which outcomes based practices have been developed. Both technical aspects of PVE including volumetry, approaches, and embolization agents; and clinical aspects of PVE including data supporting indications, and its role in conjunction with chemotherapy and transarterial embolization will be highlighted. PVE remains an important aspect of oncologic care; in large part due to the substantial foundation of information available demonstrating its clear clinical benefit for hepatic resection candidates with small anticipated FLRs.

Preoperative portal vein embolization in liver cancer: indications, techniques and outcomes

Postoperative liver failure is a severe complication of major hepatectomies, in particular in patients with a chronic underlying liver disease. Portal vein embolization (PVE) is an approach that is gaining increasing acceptance in the preoperative treatment of selected patients prior to major hepatic resection. Induction of selective hypertrophy of the non-diseased portion of the liver with PVE in patients with either primary or secondary hepatobiliary, malignancy with small estimated future liver remnants (FLR) may result in fewer complications and shorter hospital stays following resection. Additionally, PVE performed in patients initially considered unsuitable for resection due to lack of sufficient remaining normal parenchyma may add to the pool of candidates for surgical treatment. A thorough knowledge of hepatic segmentation and portal venous anatomy is essential before performing PVE. In addition, the indications and contraindications for PVE, the methods for assessing hepatic lobar hypertrophy, the means of determining optimal timing of resection, and the possible complications of PVE need to be fully understood before undertaking the procedure. Technique may vary among operators, but cyanoacrylate glue seems to be the best embolic agent with the highest expected rate of liver regeneration for PVE. The procedure is usually indicated when the remnant liver accounts for less than 25-40% of the total liver volume. Compensatory hypertrophy of the non-embolized segments is maximal during the first 2 weeks and persists, although to a lesser extent during approximately 6 weeks. Liver resection is performed 2 to 6 weeks after embolization. The goal of this article is to discuss the rationale, indications, techniques and outcomes of PVE before major hepatectomy.

Acetaminophen metabolism after liver resection: A prospective case-control study

BACKGROUND

The effect of liver resection on acetaminophen metabolism and whether it is affected by residual liver volume is poorly understood.

METHODS

We investigated the effects of liver resection on acetaminophen metabolism in a single centre, prospective observational, case-control study of inpatients. Patients undergoing liver resection were administered therapeutic post-operative acetaminophen. Glutathione and urinary acetaminophen metabolites were measured over the first three post-operative days and compared between patients with low (Group A) and high (Group B) residual liver volume.

RESULTS

41 patients (41% female, median age 62 [IQR 53-72] years) were included. Mean urinary cysteine levels increased significantly from post-operative day 1 to 2 (578.0 mg/day 95% CI 478.9-677.1 vs. 775.4 mg/day, 95% CI 625.7-925.1; p=0.03). Group A (n=11) had significantly higher median levels of cysteine (day 1, 464.3 mg/day [IQR 355.6-582.0]; day 3, 717.6 mg/day [IQR 423.5-1104.0]) compared to Group B (n=11): day 1, 545.4 mg/day (IQR 346.9-843.5); day 3, 508.1mg/day (IQR 390.8-788.4; p=0.048). No significant difference was observed in glutathione or 5-oxoproline levels between the groups.

CONCLUSION

Low residual liver volume results in altered acetaminophen metabolism, however, no evidence of glutathione deficiency was observed. Therapeutic acetaminophen is safe after major liver resection provided liver function is adequate.

Defining Post Hepatectomy Liver Insufficiency: Where do We stand?

BACKGROUND

Post-hepatectomy liver failure (PHLF) is a major source of morbidity and mortality in patients undergoing liver resection. The aim of this review is to summarize the recent literature available on PHLF including its definition, predictive factors, preoperative risk assessment, severity grading, preventative measures, and management strategies.

METHODS

A systematic literature search was carried out with the search engines PubMed, Medline, and Cochrane Database using the keywords related to "liver failure", "posthepatectomy", and "hepatic resection".

RESULTS

Liver resection is a curative treatment of liver tumors. However, it leads to concurrent death and regeneration of the remaining hepatocytes. Factors related to the patient, liver parenchyma and the extent of surgery can inhibit regeneration leading to PHLF.

CONCLUSION

Given its resistance to treatment and the high postoperative mortality associated with PHLF, great effort has been put in to both accurately identify patients at high risk and to develop strategies that can help prevent its occurrence.

Quantitative assessment of hepatic function: modified look-locker inversion recovery (MOLLI) sequence for T1 mapping on Gd-EOB-DTPA-enhanced liver MR imaging

OBJECTIVES

To determine whether multislice T1 mapping of the liver using a modified look-locker inversion recovery (MOLLI) sequence on gadoxetic acid-enhanced magnetic resonance imaging (MRI) can be used as a quantitative tool to estimate liver function and predict the presence of oesophageal or gastric varices.

METHODS

Phantoms filled with gadoxetic acid were scanned three times using MOLLI sequence to test repeatability. Patients with chronic liver disease or liver cirrhosis who underwent gadoxetic acid-enhanced liver MRI including MOLLI sequence at 3 T were included (n = 343). Pre- and postcontrast T1 relaxation times of the liver (T1liver), changes between pre- and postcontrast T1liver (ΔT1liver), and adjusted postcontrast T1liver (postcontrast T1liver-T1spleen/T1spleen) were compared among Child-Pugh classes. In 62 patients who underwent endoscopy, all T1 parameters and spleen sizes were correlated with varices.

RESULTS

Phantom study showed excellent repeatability of MOLLI sequence. As Child-Pugh scores increased, pre- and postcontrast T1liver were significantly prolonged (P < 0.001), and ΔT1liver and adjusted postcontrast T1liver decreased (P < 0.001). Adjusted postcontrast T1liver and spleen size were independently associated with varices (R (2) = 0.29, P < 0.001).

CONCLUSIONS

T1 mapping of the liver using MOLLI sequence on gadoxetic acid-enhanced MRI demonstrated potential in quantitatively estimating liver function, and adjusted postcontrast T1liver was significantly associated with varices.

KEY POINTS

• T1 mapping using MOLLI sequence can be achieved within a breath-hold. • T1liver measured by MOLLI sequence provided excellent short-term repeatability. • Precontrast and postcontrast T1liver were significantly prolonged as Child-Pugh scores increased. • Adjusted postcontrast T1liver and spleen size were independently associated with varices.

Impact of Neoadjuvant Chemotherapy on Hypertrophy of the Future Liver Remnant after Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy

BACKGROUND

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) has been demonstrated as a feasible procedure in extended liver resections as a means of successfully increasing the volume of the future liver remnant (FLR). Neoadjuvant chemotherapy (CTx) is toxic to the organ and may impair hepatic regeneration. This study was performed to assess the procedure's effect on hypertrophy of the FLR, including the short-term survival.

STUDY DESIGN

We analyzed 19 consecutive ALPPS patients, of whom 58% (n = 11) received neoadjuvant CTx because of colorectal liver metastasis (CRM). Patients presented with multifocal CRM (n = 11, 58%); cholangiocarcinoma (n = 7, 37%), of which 5 were in the Klatskin position; and gallbladder carcinoma (n = 1, 5%). Hepatectomy was performed within 6 to 13 days after hepatic partition. Volumetry was performed before both liver partitioning and hepatectomy. A survival analysis was performed.

RESULTS

Liver partition and portal vein ligation induced sufficient hypertrophy of the FLR, with an increased volume of 74% ± 35%. Patients underwent hepatectomy after a median of 8 days; in all cases R0 resection was achieved. Neoadjuvant CTx was shown to significantly impair hypertrophy. The volume of the FLR in non-CTx patients increased by 98% ± 35%; an increase of 59% ± 22% was observed in patients who underwent CTx (p = 0.027). Chemotherapy did not have an impact on either morbidity or in-hospital mortality, which were 68% and 16%, respectively. One-year overall survival was 53%, with a 1-year survival of 67% in CRM patients and 38% in non-CRM patients (p > 0.05).

CONCLUSIONS

Data presented here demonstrate for the first time that neoadjuvant CTx significantly impairs hypertrophy of the FLR after ALPPS.

Strategies to increase the resectability of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is best treated by liver transplantation, but the applicability of transplantation is greatly limited. Tumor resection in partial hepatectomy is hence resorted to. However, in most parts of the world, only 20%-30% of HCCs are resectable. The main reason for such a low resectability is a future liver remnant too small to be sufficient for the patient. To allow more HCC patients to undergo curative hepatectomy, a variety of ways have been developed to increase the resectability of HCC, mainly ways to increase the future liver remnants in patients through hypertrophy. They include portal vein embolization, sequential transarterial chemoembolization and portal vein embolization, staged hepatectomy, two-staged hepatectomy with portal vein ligation, and Associating Liver Partition and Portal Vein Ligation in Staged Hepatectomy. Herein we review, describe and evaluate these different ways, ways that can be life-saving.

Computer-assisted liver tumor surgery using a novel semiautomatic and a hybrid semiautomatic segmentation algorithm

We developed a medical image segmentation and preoperative planning application which implements a semiautomatic and a hybrid semiautomatic liver segmentation algorithm. The aim of this study was to evaluate the feasibility of computer-assisted liver tumor surgery using these algorithms which are based on thresholding by pixel intensity value from initial seed points. A random sample of 12 patients undergoing elective high-risk hepatectomies at our institution was prospectively selected to undergo computer-assisted surgery using our algorithms (June 2013-July 2014). Quantitative and qualitative evaluation was performed. The average computer analysis time (segmentation, resection planning, volumetry, visualization) was 45 min/dataset. The runtime for the semiautomatic algorithm was <0.2 s/slice. Liver volumetric segmentation using the hybrid method was achieved in 12.9 s/dataset (SD ± 6.14). Mean similarity index was 96.2 % (SD ± 1.6). The future liver remnant volume calculated by the application showed a correlation of 0.99 to that calculated using manual boundary tracing. The 3D liver models and the virtual liver resections had an acceptable coincidence with the real intraoperative findings. The patient-specific 3D models produced using our semiautomatic and hybrid semiautomatic segmentation algorithms proved to be accurate for the preoperative planning in liver tumor surgery and effectively enhanced the intraoperative medical image guidance.

Call for standardized definitions of osteoarthritis and risk stratification for clinical trials and clinical use

Osteoarthritis (OA) is a heterogeneous disorder. The goals of this review are (1) To stimulate use of standardized nomenclature for OA that could serve as building blocks for describing OA and defining OA phenotypes, in short to provide unifying disease concepts for a heterogeneous disorder; and (2) To stimulate establishment of ROAD (Risk of OA Development) and ROAP (Risk of OA Progression) tools analogous to the FRAX™ instrument for predicting risk of fracture in osteoporosis; and (3) To stimulate formulation of tools for identifying disease in its early preradiographic and/or molecular stages - REDI (Reliable Early Disease Identification). Consensus around more sensitive and specific diagnostic criteria for OA could spur development of disease modifying therapies for this entity that has proved so recalcitrant to date. We fully acknowledge that as we move forward, we expect to develop more sophisticated definitions, terminology and tools.

Integrating Chemotherapy into the Management of Oligometastatic Colorectal Cancer: Evidence-Based Approach Using Clinical Trial Findings

BACKGROUND

This study used case reports to review the role of systemic chemotherapy in oligometastatic colorectal cancer (CRC) and to suggest ways to integrate clinical research findings into the interdisciplinary management of this potentially curable subset of patients.

METHODS

This educational review discusses the role of chemotherapy in the management of oligometastatic metastatic CRC.

RESULTS

In initially resectable oligometastatic CRC, the goal of chemotherapy is to eradicate micrometastatic disease. Perioperative 5-fluorouracil and oxaliplatin together with surgical resection can result in 5-year survival rates as high as 57 %. With the development of increasingly successful chemotherapy regimens, attention is being paid to chemotherapy used to convert patients with initially unresectable metastasis to patients with a chance of surgical cure. The choice of chemotherapy regimen requires consideration of the goals for therapy and assessment of both tumor- and patient-specific factors.

CONCLUSION

This report discusses the choice and timing of chemotherapy in patients with initially resectable and borderline resectable metastatic CRC. Coordinated multidisciplinary care of such patients can optimize survival outcomes and result in cure for patients with this otherwise lethal disease.

Update in management of hepatocellular carcinoma in Eastern population

Hepatocellular carcinoma (HCC) is one of the commonest malignant tumours in the East. Although the management of HCC in the West is mainly based on the Barcelona Clinic for Liver Cancer staging, it is considered too conservative by Asian countries where the number of HCC patients is huge. Scientific and clinical advances were made in aspects of diagnosis, staging, and treatment of HCC. HCC is well known to be associated with cirrhosis and the treatment of HCC must take into account the presence and stage of chronic liver disease. The major treatment modalities of HCC include: (1) surgical resection; (2) liver transplantation; (3) local ablation therapy; (4) transarterial locoregional treatment; and (5) systemic treatment. Among these, resection, liver transplantation and ablation therapy for small HCC are considered as curative treatment. Portal vein embolisation and the associating liver partition with portal vein ligation for staged hepatectomy may reduce dropout in patients with marginally resectable disease but the midterm and long-term results are still to be confirmed. Patient selection for the best treatment modality is the key to success of treatment of HCC. The purpose of current review is to provide a description of the current advances in diagnosis, staging, pre-operative liver function assessment and treatment options for patients with HCC in the east.

Multidisciplinary perspective of hepatocellular carcinoma: A Pacific Northwest experience

Hepatocellular carcinoma (HCC) is the most rapidly increasing type of cancer in the United States. HCC is a highly malignant cancer, accounting for at least 14000 deaths in the United States annually, and it ranks third as a cause of cancer mortality in men. One major difficulty is that most patients with HCC are diagnosed when the disease is already at an advanced stage, and the cancer cannot be surgically removed. Furthermore, because almost all patients have cirrhosis, neither chemotherapy nor major resections are well tolerated. Clearly there is need of a multidisciplinary approach for the management of HCC. For example, there is a need for better understanding of the fundamental etiologic mechanisms that are involved in hepatocarcinogenesis, which could lead to the development of successful preventive and therapeutic modalities. It is also essential to define the cellular and molecular bases for malignant transformation of hepatocytes. Such knowledge would: (1) greatly facilitate the identification of patients at risk; (2) prompt efforts to decrease risk factors; and (3) improve surveillance and early diagnosis through diagnostic imaging modalities. Possible benefits extend also to the clinical management of this disease. Because there are many factors involved in pathogenesis of HCC, this paper reviews a multidisciplinary perspective of recent advances in basic and clinical understanding of HCC that include: molecular hepatocarcinogenesis, non-invasive diagnostics modalities, diagnostic pathology, surgical modality, transplantation, local therapy and oncological/target therapeutics.

A comparison of portal vein embolization with poly(2-hydroxyethylmethacrylate) and a histoacryl/lipiodol mixture in patients scheduled for extended right hepatectomy

To determine whether PHEMA [poly(2-hydroxyethylmethacrylate)] is suitable for portal vein embolization in patients scheduled to right hepatectomy and whether it is as effective as the currently used agent (a histoacryl/lipiodol mixture). Two groups of nine patients each scheduled for extended right hepatectomy for primary or secondary hepatic tumor, had right portal vein embolization in an effort to induce future liver remnant (FLR) hypertrophy. One group had embolization with PHEMA, the other one with the histoacryl/lipiodol mixture. In all patients, embolization was performed using the right retrograde transhepatic access. Embolization was technically successful in all 18 patients, with no complication related to the embolization agent. Eight patients of either group developed FLR hypertrophy allowing extended right hepatectomy. Likewise, one patient in each group had recanalization of a portal vein branch. Histology showed that both embolization agents reach the periphery of portal vein branches, with PHEMA penetrating somewhat deeper into the periphery. PHEMA has been shown to be an agent suitable for embolization in the portal venous system comparable with existing embolization agent (histoacryl/lipiodol mixture).

Safety and long-term outcomes of anatomic left hepatic trisectionectomy for intermediate and advanced hepatocellular carcinoma

BACKGROUND AND AIM

Anatomic left hepatic trisectionectomy (ALHT) is a complex hepatic resection, and its outcomes in hepatocellular carcinoma (HCC) still remain unclear. This paper focuses on the assessment of the safety and long-term effects of ALHT on intermediate and advanced HCC patients with tumors that occupy the left liver lobe.

METHODS

This study performed a retrospective analysis of consecutive HCC patients who underwent ALHT in a single-center cohort between December 2004 and December 2011.

RESULTS

ALHT was performed on 34 intermediate and advanced HCC patients (0.05%) of 17064 HCC patients who had undergone hepatic resection. Among them, 12 (33.3%) developed postoperative complications. Based on the multivariate analysis, we found that a serum prealbumin level of 170 mg/L is associated with an increased risk of morbidity (P=0.008). The one-year, two-year, three-year, and five-year overall survival rates were 61%, 27%, 11%, and 11%, respectively. The median overall survival was 13 months (range, 2-89 months). Based on the multivariate analysis, we also found that patients with an A/G ratio <1.5 are more likely to have poor prognosis than those with an A/G ratio ≥ 1.5 (P=0.014). Multiple tumors are associated with worse outcomes (P=0.020).

CONCLUSIONS

ALHT is safe for intermediate and advanced HCC patients with tumors that occupy the left lobe and with preoperative Child-Pugh class A liver function. Low preoperative serum prealbumin level may increase the risk of postoperative complications. Although early intrahepatic recurrence rate is high, some patients, especially those with a single tumor and normal A/G ratio, exhibit long-term survival.

The value of the combination of fibrosis index based on the four factors and future liver remnant volume ratios as a predictor on posthepatectomy outcomes

BACKGROUND

Liver fibrosis and cirrhosis are well-known risk factors for morbidity and mortality after hepatectomy. Fibrosis index based on the four factors (FIB-4) is a non-invasive method for detection of hepatic fibrosis and cirrhosis with high accuracy. This study aimed to evaluate the predictive value of future liver remnant volume ratios (FLRVR)/FIB-4 after liver resection for posthepatectomy outcomes in patients with fibrosis and cirrhosis.

METHODS

All patients with severe fibrosis or cirrhosis who underwent a liver resection (≥2 segments) were included. Liver insufficiency was defined according to grade C posthepatectomy liver failure (PLF) proposed by the International Study Group of Liver Surgery (ISGLS). Receiver operating characteristic curves and logistic regression model were used to determine the optimal cutoff of FLRVR/FIB-4 and independent risk factors of postoperative outcomes.

RESULTS

The study population consisted of 338 patients. FLRVR/FIB-4 was gradually correlated with short-term outcomes. The optimal value of FLRVR/FIB-4 to predict PLF was 0.13 when considering grade C PLF and postoperative death. A value of 0.24 best predicted postoperative morbidity. At multivariate analysis, FLRVR/FIB-4 remained an independent predictor of PLF (risk ratio(RR) = 0.046; 95% confidence interval (CI): 0.010-0.215; P < 0.001), postoperative morbidity (RR = 0.272; 95% CI: 0.167-0.445; P < 0.001) and mortality(RR =0.058; 95% CI: 0.012-0.277; P < 0.001).

CONCLUSION

FLRVR/FIB-4 is an independent predictive factor of postoperative outcomes after liver resection in patients with cirrhosis. It is a useful preoperative investigation for risk stratification before hepatectomy.

The inhomogeneous distribution of liver function: possible impact on the prediction of post-operative remnant liver function

BACKGROUND

Previous studies have shown that liver function is inhomogeneously distributed in diseased livers, and this uneven distribution cannot be compensated for if a global liver function test is used for the prediction of post-operative remnant liver function. Dynamic Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) can assess segmental liver function, thus offering the possibility to overcome this problem.

METHODS

In 10 patients with liver cirrhosis and 10 normal volunteers, the contribution of individual liver segments to total liver function and volume was calculated using dynamic Gd-EOB-DTPA-enhanced MRI. Remnant liver function predictions using a segmental method and global assessment were compared for a simulated left hemihepatectomy. For the prediction based on segmental functional MRI assessment, the estimated function of the remnant liver segments was added.

RESULTS

Global liver function assessment overestimated the remnant liver function in 9 out of 10 patients by as much as 9.3% [median -3.5% (-9.3-3.5%)]. In the normal volunteers there was a slight underestimation of remnant function in 9 out of 10 cases [median 1.07% (-0.7-2.5%)].

DISCUSSION

The present study underlines the necessity of a segmental liver function test able to compensate for the non-homogeneous nature of liver function, if the prediction of post-operative remnant liver function is to be improved.

Surgical management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second most common cause of death from cancer worldwide. Standard potentially curative treatments are either resection or transplantation. The aim of this paper is to provide an overview of the surgical management of HCC, as well as highlight current issues in hepatic resection and transplantation. In summary, due to the relationship between HCC and chronic liver disease, the management of HCC depends both on tumour-related and hepatic function-related considerations. As such, HCC is currently managed largely through non-surgical means as the criteria, in relation to the above considerations, for surgical management is still largely restrictive. For early stage tumours, both resection and transplantation offer fairly good survival outcomes (5 years overall survival of around 50%). Selection therefore would depend on the level of hepatic function derangement, organ availability and local expertise. Patients with intermediate stage cancers have limited options, with resection being the only potential for cure. Otherwise, locoregional therapy with transarterial chemoembolization or radiofrequency ablation are viable options. Current issues in resection and transplantation are also briefly discussed such as laparoscopic resection, ablation vs resection, anatomical vs non-anatomical resection, transplantation vs resection, living donor liver transplantation and salvage liver transplantation.

Volumetric analysis and indocyanine green retention rate at 15 min as predictors of post-hepatectomy liver failure

OBJECTIVES

The actual future liver remnant (aFLR) is calculated as the ratio of remnant liver volume (RLV) to total functional liver volume (TFLV). The standardized future liver remnant (sFLR) is calculated as the ratio of RLV to standard liver volume (SLV). The aims of this study were to compare the aFLR with the sFLR and to determine criteria for safe hepatectomy using computed tomography volumetry and indocyanine green retention rate at 15 min (ICG R15).

METHODS

Medical records and volumetric measurements were obtained retrospectively for 81 patients who underwent right hemi-hepatectomy for malignant hepatic tumours from January 2010 to November 2013. The sFLR was compared with the aFLR, and a ratio of sFLR to ICG R15 as a predictor of postoperative hepatic function was established.

RESULTS

In patients without cirrhosis, the sFLR showed a stronger correlation with the total serum bilirubin level than the aFLR (R(2) = 0.499 versus R(2) = 0.239). Post-hepatectomy liver failure developed only in the group with an sFLR of <25%, regardless of ICG R15. In patients with cirrhosis, the aFLR and sFLR had no correlation with postoperative total serum bilirubin. An sFLR : ICG R15 ratio of >1.9 showed 66.7% sensitivity and 100% specificity.

CONCLUSIONS

Regardless of ICG R15, an sFLR of ≥ 25% in patients without cirrhosis, and an sFLR of ≥ 25% with an sFLR : ICG R15 ratio of >1.9 in patients with cirrhosis indicate acceptable levels of safety in major hepatectomy.

Recent advances in estimating hepatic functional reserve in patients with chronic liver damage

Preoperative estimation of liver functional reserve is important in liver surgery to prevent postoperative liver failure. Although the hepatic functional reserve of patients with chronic liver disease is generally evaluated by measuring indocyanine green dye retention at 15 min, no standard method of estimating regional liver function has been established to date. Several recently introduced imaging modalities, such as hepatobiliary scintigraphy and magnetic resonance imaging with gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid, may be used to evaluate liver function. Here, we review recent advances in estimating hepatic functional reserve, mainly by radiological modalities, in patients with chronic liver damage.

Volume regeneration of segments 2 and 3 after right portal vein embolization in patients undergoing two-stage hepatectomy

BACKGROUND

The impact of first-stage resection on volume regeneration of segments 2 and 3 (2 + 3) after right portal vein embolization (RPVE) in patients undergoing two-stage right hepatectomy has not been investigated.

METHOD

Volume data for segments 2 + 3 were compared between 44 patients undergoing two-stage hepatectomy and 116 undergoing single-stage hepatectomy after RPVE.

RESULTS

The degree of hypertrophy (difference between standardized volume of segments 2 + 3 before and after RPVE) and kinetic growth rate (degree of hypertrophy at initial volume assessment divided by the number of weeks elapsed after RPVE) were significantly lower in patients undergoing two-stage hepatectomy (median 8.6 vs 10.5% [p = 0.01] and 1.7 vs 2.4% [p < 0.01], respectively). Resection volume during first-stage resection was negatively correlated with standardized volume increase from the volume before first-stage resection (R (2) 0.546, p < 0.01). In patients undergoing two-stage hepatectomy after RPVE with segment 4 embolization, the degree of hypertrophy and kinetic growth rate were similar to those in patients undergoing single-stage hepatectomy (p = 0.17 and p = 0.08, respectively).

CONCLUSION

In patients undergoing two-stage hepatectomy, first-stage resection impairs the dynamics of volume regeneration of segments 2 + 3 after RPVE. When two-stage extended right hepatectomy is planned, additional embolization of segment 4 provides volume hypertrophy similar to that in patients undergoing single-stage hepatectomy.

Accuracy of preoperative automatic measurement of the liver volume by CT-scan combined to a 3D virtual surgical planning software (3DVSP)

BACKGROUND

Liver volumetry is a critical component of safe hepatic surgery, in order to minimize the risk of postoperative liver failure. Liver volumes can be calculated routinely using the time-consuming gold standard method of manual volumetry. The current work sought to evaluate an alternative automatic technique based on a novel 3D virtual planning software, and to compare it to the manual technique.

METHODS

A prospective study of patients undergoing liver resection was conducted. Every patient had a pre and 2-day postoperative CT-scan. For each patient, total, remnant and resected volumes were calculated manually and automatically. Planes of resection were verified by a hepatobiliary surgeon and compared with postoperative volumes. Paired t-tests and correlation coefficients were calculated.

RESULTS

A major hepatectomy was carried out in 36/43 patients. The automatic TLV (1,759 mL) and the manual TLV (1,832 mL) were significantly different (p < 0.001), but extremely highly correlated (r = 0.989). The percentages of preoperative RLV (manual 58.5%, automatic 58.9%) were similar, with an excellent correlation of 0.917. The preoperative RLV were matched with the 2-day postoperative RLV showing a significant difference (p = 0.0301). The resected volumes using both techniques (871 and 832 mL) were compared with the resected specimen volume (670 mL), showing a significant difference (p < 0.001) but a high degree of correlation (r = 0.874).

CONCLUSION

The 3D virtual surgical planning software is accurate and reliable in determining the total liver and future remnant liver volumes. This technique demonstrates a good correlation with the manual technique. Future work will be required to confirm these findings and to evaluate the clinical value of the three-dimensional planning platform.

Small for size liver remnant following resection: prevention and management

In the latest decades an important change was registered in liver surgery, however the management of liver cirrhosis or small size hepatic remnant still remains a challenge. Currently post-hepatectomy liver failure (PLF) is the major cause of death after liver resection often associated with sepsis and ischemia-reperfusion injury (IRI). ''Small-for-size'' syndrome (SFSS) and PFL have similar mechanism presenting reduction of liver mass and portal hyper flow beyond a certain threshold. Few methods are described to prevent both syndromes, in the preoperative, perioperative and postoperative stages. Additionally to portal vein embolization (PVE), radiological examinations (mainly CT and/or MRI), and more recently 3D computed tomography are fundamental to quantify the liver volume (LV) at a preoperative stage. During surgery, in order to limit parenchymal damage and optimize regenerative capacity, some hepatoprotective measures may be employed, among them: intermittent portal clamping and hypothermic liver preservation. Regarding the treatment, since PLF is a quite complex disease, it is required a multi-disciplinary approach, where it management must be undertaken in conjunction with critical care, hepatology, microbiology and radiology services. The size of the liver cannot be considered the main variable in the development of liver dysfunction after extended hepatectomies. Additional characteristics should be taken into account, such as: the future liver remnant; the portal blood flow and pressure and the exploration of the potential effects of regeneration preconditioning are all promising strategies that could help to expand the indications and increase the safety of liver surgery.

Complications following hepatectomy

As the number of liver resections in the United States has increased, operations are more commonly performed on older patients with multiple comorbidities. The advent of effective chemotherapy and techniques such as portal vein embolization, have compounded the number of increasingly complex resections taking up to 75% of healthy livers. Four potentially devastating complications of liver resection include postoperative hemorrhage, venous thromboembolism, bile leak, and post-hepatectomy liver failure. The risk factors and management of these complications are herein explored, stressing the importance of identifying preoperative factors that can decrease the risk for these potentially fatal complications.

Intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is a rare tumor, with an increasing incidence worldwide and an overall poor prognosis. Symptoms are usually nonspecific, contributing to an advanced tumor stage at diagnosis. The staging system for ICC has recently been updated and is based on number of lesions, vascular invasion, and lymph node involvement. Complete surgical resection to negative margins remains the only potentially curable treatment for ICC. Gemcitabine-based adjuvant therapy can be offered based on limited data from patients with unresectable ICC. Overall 5-year survivals after resection range from 17% to 44%, with median survivals of 19 to 43 months.

New perspectives in the assessment of future remnant liver

In order to achieve microscopic radical resection margins and thus better survival, surgical treatment of hepatic tumors has become more aggressive in the last decades, resulting in an increased rate of complex and extended liver resections. Postoperative outcomes mainly depend on the size and quality of the future remnant liver (FRL). Liver resection, when performed in the absence of sufficient FRL, inevitably leads to postresection liver failure. The current gold standard in the preoperative assessment of the FRL is computed tomography volumetry. In addition to the volume of the liver remnant after resection, postoperative function of the liver remnant is directly related to the quality of liver parenchyma. The latter is mainly influenced by underlying diseases such as cirrhosis and steatosis, which are often inaccurately defined until microscopic examination after the resection. Postresection liver failure remains a point of major concern that calls for accurate methods of preoperative FRL assessment. A wide spectrum of tests has become available in the past years, attesting to the fact that the ideal methodology has yet to be defined. The aim of this review is to discuss the current modalities available and new perspectives in the assessment of FRL in patients scheduled for major liver resection.

Using Dynamic 99mT c-GSA SPECT/CT fusion images for hepatectomy planning and postoperative liver failure prediction

BACKGROUND

Available tools in liver surgery planning rely on the future remnant liver (FRL) volume. Inappropriate decision might be made since the same FRL volume might represent different liver functions depending on the severity of underlying liver damage. This study developed an alternative system to estimate FRL function and to predict the risk of postoperative liver failure.

METHODS

Current study recruited 71 prehepatectomy patients and 71 healthy volunteers. A technetium-99-labelled asialoglycoproteins was given to participants and SPECT was used to capture the intensity of the signal, represented by uptake index (UI). The agreement between preoperative UI values, liver function tests, and Child scores were evaluated. Linear regression was used to evaluate the agreement between predicted UI for FRL and postoperative UI values. Area under the receiver operating characteristic (AUC) curve was used to evaluate the discriminative performance of UI in differentiating patient with high risk of liver failure.

RESULTS

Preoperative UIs are highly correlated with Child score (P < 0.0001), especially to identify patients with ascites and elevated bilirubin. The predicted UIs were in close agreement with the actual postoperative UI values (r = 0.95 P < 0.001). The AUC analysis indicated that UI values had a high accuracy in predicting the risk of liver failure (AUC = 0.95, P < 0.0001). The best cut-off point was 0.9 and the corresponding sensitivity was 100 % and specificity was 92 %.

CONCLUSIONS

The new methodology reliably estimates FRL function and predicts the risk of liver failure. It provides a visual aid for liver surgeon in surgery planning and risk assessment.

Liver-directed therapies in metastatic colorectal cancer

Colorectal cancer (CRC) is a major health concern in the United States (US) with over 140,000 new cases diagnosed in 2012. The most common site for CRC metastases is the liver. Hepatic resection is the treatment of choice for colorectal liver metastases (CLM), with a 5-year survival rate ranging from 35% to 58%. Unfortunately, only about 20% of patients are eligible for resection. There are a number of options for extending resection to more advanced patients including systemic chemotherapy, portal vein embolization (PVE), two stage hepatectomy, ablation and hepatic artery infusion (HAI). There are few phase III trials comparing these treatment modalities, and choosing the right treatment is patient dependent. Treating hepatic metastases requires a multidisciplinary approach and knowledge of all treatment options as there continues to be advances in management of CLM. If a patient can undergo a treatment modality in order to increase their potential for future resection this should be the primary goal. If the patient is still deemed unresectable then treatments that lengthen disease-free and overall-survival should be pursued. These include chemotherapy, ablation, HAI, chemoembolization, radioembolization (RE) and stereotactic radiotherapy.

The liver protective effect of methylprednisolone on a new experimental acute-on-chronic liver failure model in rats

BACKGROUND

Acute-on-chronic liver failure is a severe, life-threatening entity and the comprehension of this disease is incomplete. Currently, a reasonable surgical model of acute-on-chronic liver failure is still lacking. The aim of this study was to establish a new model of acute-on-chronic liver failure in rats and to investigate the protective effects of methylprednisolone on this model.

METHODS

An obstructive jaundice model in rats was established. Two weeks later, the animals were subjected to a choledochoduodenostomy and a reduced-size hepatic ischaemia/reperfusion injury. Animals were randomly divided into a control group, a methylprednisolone injected via the tail vein group and a methylprednisolone injected via the portal vein group. The survival rates and serum levels of alanine transaminase, aspartate aminotransferase, total bilirubin, tumour necrosis factor alpha, and interferon gamma of the rats were measured and the pathological changes in liver tissues were observed.

RESULTS

The survival rate was significantly improved in the methylprednisolone treatment groups. Serum levels of the biochemical indexes were the lowest in the portal vein injection group. Liver tissues under microscopy presented severe pathological injury in the control group.

CONCLUSION

This model could be useful for further research into acute-on-chronic liver failure and methylprednisolone may be a potential therapeutic agent for this disease.

The surgical treatment of patients with colorectal cancer and liver metastases in the setting of the "liver first" approach

A surgical resection is the only curative method in the therapy of colorectal carcinoma and liver metastases. Along with the development of interventional radiological techniques the indications for surgery widen. The number of metastases and patients age should not present a contraindication for surgical resection. However, there are still some doubts concerns what to resect first in cases of synchronous colorectal carcinoma and liver metastases and how to ensure the proper remnant liver volume in order to avoid postoperative liver failure and achieve the best results. Through this review the surgical therapy of colorectal carcinoma and liver metastases was revised in the setting of "liver-first" approach and the problem of ensuring of remnant liver volume.

Therapeutic value of transcatheter arterial chemoembolization combined with portal vein embolization for primary hepatocellular carcinoma with portal vein tumor thrombus: a pilot study

AIM

To compare clinical outcome and safety of transcatheter arterial chemoembolization (TACE) + portal vein embolization (PVE) with TACE alone in hepatocellular carcinoma (HCC) patients with portal vein tumor thrombus (PVTT).

METHODS

We retrospectively collected patients of HCC with PVTT treated with TACE (5-FU, oxaliplatin and mitomycin) or TACE + PVE (doxorubicin) between October 2000 and July 2008. Outcomes evaluated include overall survival, response to treatment and side effects.

RESULTS

One hundred and sixteen patients were assessed. The median follow-up of TACE group and TACE + PVE group was 83 and 85 months, respectively. The tumor response rates were respectively 48/64 and 49/52. The 1-, 3- and 5-year overall survival rates for the TACE and TACE + PVE groups were 39/64, 16/64, 0/64 and 42/52, 19/52, 6/52 respectively (P = 0.015, 0.046 and 0.002, respectively). Three factors were shown as the risk factors which affect the survival of patients: treated by TACE + PVE or TACE; type of PVTT; and absence of cirrhosis.

CONCLUSION

TACE + PVE may be better than TACE alone to treat primary HCC with PVTT.

Liver planning software accurately predicts postoperative liver volume and measures early regeneration

BACKGROUND

Postoperative or remnant liver volume (RLV) after hepatic resection is a critical predictor of perioperative outcomes. This study investigates whether the accuracy of liver surgical planning software for predicting postoperative RLV and assessing early regeneration.

STUDY DESIGN

Patients eligible for hepatic resection were approached for participation in the study from June 2008 to 2010. All patients underwent cross-sectional imaging (CT or MRI) before and early after resection. Planned remnant liver volume (pRLV) (based on the planned resection on the preoperative scan) and postoperative actual remnant liver volume (aRLV) (determined from early postoperative scan) were measured using Scout Liver software (Pathfinder Therapeutics Inc.). Differences between pRLV and aRLV were analyzed, controlling for timing of postoperative imaging. Measured total liver volume (TLV) was compared with standard equations for calculating volume.

RESULTS

Sixty-six patients were enrolled in the study from June 2008 to June 2010 at 3 treatment centers. Correlation was found between pRLV and aRLV (r = 0.941; p < 0.001), which improved when timing of postoperative imaging was considered (r = 0.953; p < 0.001). Relative volume deviation from pRLV to aRLV stratified cases according to timing of postoperative imaging showed evidence of measurable regeneration beginning 5 days after surgery, with stabilization at 8 days (p < 0.01). For patients at the upper and lower extremes of liver volumes, TLV was poorly estimated using standard equations (up to 50% in some cases).

CONCLUSIONS

Preoperative virtual planning of future liver remnant accurately predicts postoperative volume after hepatic resection. Early postoperative liver regeneration is measureable on imaging beginning at 5 days after surgery. Measuring TLV directly from CT scans rather than calculating based on equations accounts for extremes in TLV.

Preoperative assessment of postoperative liver function: the importance of residual liver volume

An inadequate volume of future liver remnant (FLR) remains an absolute contraindication to liver resection. FLR measurement correlates with surgical outcome and is fundamental to identify those patients that may benefit from portal vein embolization (PVE) and to assess the liver volume change following embolization. In order to minimize the risk of postoperative liver failure, preoperative analysis of FLR must be included in the surgical planning of every major liver resection. The aims of this review are to describe the use of preoperative volumetric analysis in modern liver surgery and indications for PVE.

Small-for-size syndrome in living-donor liver transplantation using a left lobe graft

In living-donor liver transplantation with a left lobe graft, which can reduce the burden on the donor compared to right lobe graft, the main problem is small-for-size (SFS) syndrome. SFS syndrome is a multifactorial disease that includes aspects related to the graft size, graft quality, recipient factors and even technical issues. The main pathophysiology of SFS syndrome is the sinusoidal microcirculatory disturbance induced by shear stress, which is caused by excessive portal inflow into the smaller graft. The donor age, the presence of steatosis of the graft and a poor recipient status are all risk factors for SFS syndrome. To resolve SFS syndrome, portal inflow modulation, splenectomy, splenic artery modulation and outflow modulation have been developed. It is important to establish strict criteria for managing SFS syndrome. Using pharmacological interventions and/or therapeutic approaches that promote liver regeneration could increase the adequate outcomes in SFS liver transplantation. Left lobe liver transplantation could be adopted in Western countries to help resolve the organ shortage.

The safe minimally ischemic liver remnant for small-for-size syndrome in porcine hepatectomy

BACKGROUND

The minimal functional remnant liver mass or graft after an ischemic injury in hepatectomy or living donor liver transplantation (LDLT) is not clear. This study sought to determine the minimal remnant liver (MRL) size after 20 minutes hepatic inflow occlusion (HIO) and the maximal portal flow with which the liver remnant can sustain in a porcine model.

METHODS

Twenty pigs that underwent massive hepatectomy were randomly divided into 3 groups: 30% group, the remnant constituted about 30% of total liver volume (TLV); 35%+O group, the remnant constitute about 35% of TLV with 20 minutes HIO, and 30%+O group, the remnant constituted about 30% of TLV with 20 minutes of HIO. We evaluated survival rates, kinetic portal vein pressures (PVP), hemodynamics, hepatocyte metabolism, and injury.

RESULTS

The 14-day survival rate in the 30%+O group was significantly reduced compared with that of either the 30% group or the 35%+O group: l00% versus 28.6% versus 85.7% respectively (P = .009). The tissue, serum analyses, and PVP in the 30%+O group were significantly different compared with the measurements among the other groups (P < .05), revealing that the liver remnant in 30%+O group could not sustain more than 3 times baseline portal flow, whereas in 35%+O group it could sustain 2.8 times baseline portal flow.

CONCLUSIONS

Intraoperative ischemia can injure the sinusoidal endothelium, decreasing its ability to regulate portal hyperperfusion, causing less than 30% to 35% of TLV to show small-for-size syndrome or postoperative liver failure.

Efficacy and safety of portal vein embolization for two-stage hepatectomy in patients with colorectal liver metastasis

PURPOSE

To examine the efficacy and safety of portal vein embolization (PVE) when used during two-stage hepatectomy for bilobar colorectal liver metastases (CLM).

MATERIALS AND METHODS

PVE was performed as an adjunct to two-stage hepatectomy in 56 patients with CLM. Absolute future liver remnant (FLR) volumes, standardized FLR ratios, degree of hypertrophy (DH), and complications were analyzed. Segment II and III volumes and DH were also measured separately. All volumetric measurements were compared with a cohort of 96 patients (n = 37 right portal vein embolization [RPVE], n = 59 right portal vein embolization extended to segment IV portal veins [RPVE+4]) in whom PVE was performed before single-stage hepatectomy.

RESULTS

For patients who completed RPVE during two-stage hepatectomy (n = 17 of 17), mean absolute FLR volume increased from 272.1 cm(3) to 427.0 cm(3) (P < .0001), mean standardized FLR ratio increased from 0.17 to 0.26 (P < .0001), and mean DH was 0.094. For patients who completed RPVE+4 during two-stage hepatectomy (n = 38 of 39), mean FLR volume increased from 288.7 cm(3) to 424.8 cm(3) (P < .0001), mean standardized FLR increased from 0.18 to 0.26 (P < .0001), and mean DH was 0.083. DH of the FLR was not significantly different between two-stage hepatectomy and single-stage hepatectomy. Complications after PVE occurred in five (8.9%) patients undergoing two-stage hepatectomy.

CONCLUSIONS

PVE effectively and safely induced a significant DH in the FLR during two-stage hepatectomy in patients with CLM.

Is computed tomography volumetric assessment of the liver reliable in patients with cirrhosis?

OBJECTIVES

The estimation of liver volume (LV) has been widely studied in normal liver, the density of which is considered to be equivalent to 1 kg/l. In cirrhosis, volumetric evaluation and its correlation to liver mass remain unclear. The aim of this study was to evaluate the accuracy of computed tomography (CT) scanning to assess LV in patients with cirrhosis.

METHODS

Liver volume was evaluated by CT (CTLV) and correlated to the explanted liver weight (LW) in 49 patients. Liver density (LD) and its association with clinical features were analysed. Commonly used formulae for estimating LV were also evaluated. The real density of cirrhotic liver was prospectively measured in explant specimens.

RESULTS

Wide variations between CTLV (in ml) and LW (in g) were found (range: 3-748). Cirrhotic livers in patients with hepatitis B virus infection presented significantly increased LD (P = 0.001) with lower CTLV (P = 0.005). Liver volume as measured by CT was also decreased in patients with Model for End-stage Liver Disease scores of >15 (P = 0.023). Formulae estimating LV correlated poorly with CTLV and LW. The density of cirrhotic liver measured prospectively in 15 patients was 1.1 kg/l.

CONCLUSIONS

In cirrhotic liver, LV assessed by CT did not correspond to real LW. Liver density changed according to the aetiology and severity of liver disease. Commonly used formulae did not accurately assess LV.

The critical value of remnant liver volume-to-body weight ratio to estimate posthepatectomy liver failure in cirrhotic patients

BACKGROUND

The extensive use of major hepatectomy for liver malignancies with cirrhosis increases the risk of posthepatectomy liver failure (PHLF), which is associated with a high frequency of postoperative complications, mortality, and an increased length of hospital stay. Remnant liver volume-to-body weight ratio (RLV-BWR) is more specific than the ratio of RLV-to-total liver volume (RLV-TLV) in predicting postoperative course after major hepatectomy in normal liver. Patients having normal liver with an anticipated RLV-BWR ≤0.5% are at considerable risk for hepatic dysfunction and postoperative mortality. In the present study, the critical value of RLV-BWR after liver resection in cirrhotic liver was investigated.

PATIENTS AND METHODS

Thirty one patients who underwent hepatectomy for hepatocellular carcinoma in one medical treatment unit of West China Hospital from September 2012 to December 2012 were retrospectively enrolled in study. Volumetric measurements of TLV using computed tomography were obtained before hepatectomy. PHLF was diagnosed by the "50-50 criteria." The influence of RLV-TLV and RLV-BWR on the occurrence of PHLF was investigated, and the critical value of RLV-BWR was concluded.

RESULTS

According to the occurrence of PHLF, the patients were retrospectively divided into PHLF group and non-PHLF group. There were no statistical differences of preoperative indicators between the two groups. The intraoperative indicators including the resected liver volume, RLV-TLV, and RLV-BWR were statistically significant (P < 0.05) between the two groups. The postoperative indicators including total bilirubin (TBIL), international normalized ratio, and peritoneal drainage fluid at the third and the fifth day after surgery were statistically significant (P < 0.05) between the two groups. Area under the receiver operating characteristic curve (ROC curve) predicted by RLV-BWR to the incidence of PHLF was 0.864 (P = 0.019) with 95% confidence interval (95% CI = 0.608-0.819), and the sensitivity and specialty rate were 70% and 95%, which were more than 50% and 70%, respectively. It suggested that the critical value of RLV-BWR (1.4%) had a certain predictive value on PHLF. Area under the receiver operating characteristic curve predicted by RLV-TLV to the incidence of PHLF was 0.568 (P = 0.628) with 95% confidence interval (95% CI = 0.376-0.747), and the sensitivity and specialty rate were 42.9% and 82.6%, respectively. The sensitivity (42.9%) <50% suggested that the critical value of RLV-TLR (51%) had a poor predictive value on PHLF. According to the curve critical value 1.4% of RLV-BWR, the patients were divided into RLV-BWR ≥1.4% group and RLV-BWR <1.4% group, and the incidence of PHLF between the two groups was statistically significant (P = 0.006).

CONCLUSIONS

RLV-BWR was more specific than RLV-TLV in predicting PHLF after major hepatectomy of cirrhotic liver. Patients with an anticipated RLV-BWR <1.4% are at considerable risk for PHLF.

Portal vein embolization and ligation for extended hepatectomy

Portal vein occlusion through embolization or ligation (PVE, PVL) offers the possibility of increasing the future liver remnant (FLR) and thus reducing the risk of hepatic failure after extended hepatectomy We reviewed the indications, scope and applicability of PVE/PVL in treatment of primary and secondary liver tumours. A thorough PubMED, Embase, Ovid and Cochrane database search was carried out for all original articles with 30 patients or more undergoing either PVE and any patient series with PVL, irrespective of number with outcome measure in at least one of the following parameters: FLR volume change, complications, length of stay, time to surgery, proportion resectable and survival data. PVE can be performed with a technical success in 98.9 % (95 % confidence interval 97-100) patients, with a mean morbidity of 3.13 % (95 % CI 1.21-5.04) and a median in-hospital stay of 2.1 (range 1-4) days (very few papers had data on length of stay following PVE). The mean increase in volume of the FLR following PVE was 39.75 % (95 % CI 30.8-48.6) facilitating extended liver resection after a mean of 37.13 days (95 % CI 28.51-45.74) with a resectability rate of 76.88 % (95 % CI 70.91-82.84). Morbidity and mortality following such extended liver resections after PVE is 26.58 % (95 % CI 19.20-33.95) and 2.59 % (95 % CI 1.34-3.83) respectively with an in-patient stay of 13.57 days (95 % CI 9.8-17.37). However following post-PVE liver hypertrophy 6.29 % (95 % CI 2.24-10.34) patients still have post-resection liver failure and up to 14.2 % (95 % CI -8.7 to 37) may have positive resection margins. Up to 4.80 % (95 % CI 2.07-7.52) have failure of hypertrophy after PVE and 17.46 % (95 % CI 11.89-23.02) may have disease progression during the interim awaiting hypertrophy and subsequent resection. PVL has a greater morbidity and duration of stay of 5.72 % (95 % CI 0-15.28) and 10.16 days (95 % CI 6.63-13.69) respectively; as compared to PVE. Duration to surgery following PVL was greater at 53.6 days (95 % CI 32.14-75.05). PVL induced FLR hypertrophy by a mean of 64.65 % (95 % CI 0-136.12) giving a resectability rate of 63.68 % (95 % CI 56.82-70.54). PVL failed to produce enough liver hypertrophy in 7.4 % of patients (95 % CI 0-16.12). Progression of disease following PVL was 29.29 (95%CI 15.69-42.88). PVE facilitates an extended hepatectomy in patients with limited or inadequate FLR, with good short and long-term outcomes. Patients need to be adequately counselled and consented for PVE and EH in light of these data. PVL would promote hypertrophy as well, but clearly PVE has advantages as compared to PVL on account of its inherent "minimally invasive" nature, fewer complications, length of stay and its feasibility to have shorter times to surgery.

Safety and efficacy of portal vein embolization before planned major or extended hepatectomy: an institutional experience of 358 patients

INTRODUCTION

Portal vein embolization (PVE) stimulates hypertrophy of the future liver remnant (FLR) and may improve the safety of extended hepatectomy. The efficacy of PVE was evaluated.

METHODS

Records of 358 consecutive patients who underwent PVE before intended major hepatectomy at our institution from 1995 through 2012 were retrospectively reviewed.

RESULTS

One hundred twelve patients (31.3 %) had right PVE alone; 235 (65.6 %) had right PVE plus segment IV embolization. The first-session PVE completion rate was 97.8 %. The PVE complication rate was 3.9 %. The median pre-PVE and post-PVE standardized FLRs were 19.5 % (interquartile range, 15.0-25.9) and 29.7 % (interquartile range, 22.5-38.2), respectively. Two hundred forty patients (67.0 %) underwent potentially curative resection. Sixty-two patients (25.8 %) had major post-hepatectomy complications; rates of postoperative hepatic insufficiency and 90-day liver-related mortality were 8.3 and 3.8 %, respectively. The proportion of patients with colorectal liver metastasis increased from 38.6 % before 2005 to 78.2 % in 2010-2012. Despite increased use of preoperative chemotherapy, postoperative hepatic insufficiency and 90-day liver-related mortality rates dropped from 10.6 and 4.1 %, respectively, before 2010 to 2.9 and 2.9 %, respectively, in 2010-2012.

CONCLUSIONS

PVE can be safely performed with minimal morbidity. Most patients can proceed to extended hepatectomy, which is associated with a minimal mortality rate.

Liver segmentation: practical tips

The liver segmentation system, described by Couinaud, is based on the identification of the three hepatic veins and the plane passing by the portal vein bifurcation. Nowadays, Couinaud's description is the most widely used classification since it is better suited for surgery and more accurate for the localisation and monitoring of intra-parenchymal lesions. Knowledge of the anatomy of the portal and venous system is therefore essential, as is knowledge of the variants resulting from changes occurring during the embryological development of the vitelline and umbilical veins. In this paper, the authors propose a straightforward systematisation of the liver in six steps using several additional anatomical points of reference. These points of reference are simple and quickly identifiable in any radiological examination with section imaging, in order to avoid any mistakes in daily practice. In fact, accurate description impacts on many diagnostic and therapeutic applications in interventional radiology and surgery. This description will allow better preparation for biopsy, portal vein embolisation, transjugular intrahepatic portosystemic shunt, tumour resection or partial hepatectomy for transplantation. Such advance planning will reduce intra- and postoperative difficulties and complications.

Measured versus estimated total liver volume to preoperatively assess the adequacy of the future liver remnant: which method should we use?

OBJECTIVES

To determine which method of liver volumetry is more accurate in predicting a safe resection.

BACKGROUND

Before major or extended hepatectomy, assessment of the future liver remnant (FLR) is crucial to reduce the risk of postoperative hepatic insufficiency. The FLR volume is usually expressed as the ratio of FLR to nontumorous total liver volume (TLV), which can be measured directly by computed tomography (mTLV) or estimated (eTLV) on the basis of correlation existing with the body surface area. To date, these 2 methods have never been compared.

METHODS

All consecutive, noncirrhotic patients who underwent resection of 3 or more liver segments between April 2000 and April 2012 and for whom (i) preoperative computed tomographic scans and (ii) body surface area were available entered the study. The mTLV (calculated as TLV - tumor volume) was compared with the eTLV (calculated as -794.41 + 1267.28 × body surface area) using volumetric data (cm) and clinical outcome measures (specifically, hepatic insufficiency and 90-day mortality). Definition of hepatic insufficiency was peak postoperative serum total bilirubin level of more than 7 mg/dL or, in jaundiced patients, an increasing bilirubin level on day 5 or thereafter.

RESULTS

Two-hundred forty-three patients who had undergone major (n = 135) or extended (n = 108) hepatectomies met the inclusion criteria. Twenty-eight patients (11.5%) developed hepatic insufficiency, whereas 7 patients (2.9%) died postoperatively. Compared with the eTLV, the mTLV underestimated the liver volume in 60.1% of the patients (P < 0.01). Forty-seven and 73 patients had an inadequate FLR based on mTLV and eTLV, respectively. Portal vein occlusion (PVO) was used in 44 patients. In patients (n = 162) in whom both methods did not evidence the need for PVO, postoperative hepatic insufficiency and mortality were 4.9% and 0.6%, respectively. Conversely, in patients (n = 27) in whom the eTLV but not the mTLV evidenced the need for PVO, and thus PVO was not performed, hepatic insufficiency (22.2%; P = 0.001) and mortality (3.7%; P = ns) were higher.

CONCLUSIONS

The use of eTLV identifies a subset of patients (∼11%) in whom liver volumetry with the mTLV underestimates the risk of hepatic insufficiency.